Patients in hospitals, other health care facilities and home care settings may be confined to a bed for an extended period of time. Such beds may include articulable components so that the occupant or a caregiver can adjust the profile of the bed. The beds may also include components for applying selected therapies to the occupant. The use of articulating and therapeutic features may cause the occupant to migrate from an optimum location or position on the bed to another location or position, usually closer to the foot end of the bed. Even if articulating and therapeutic features are unavailable or unused, the occupant can nevertheless migrate from the optimal location to a nonoptimal location. Occupant migration refers to, for example, an involuntary change in occupant position in at least the longitudinal direction, and is distinct from intentional movements such as an occupant voluntarily repositioning himself or being repositioned by a caregiver. The migration, in addition to placing the occupant in a nonoptimal location, can also impose undesirable shear stresses on the occupant's skin. It is, therefore, desirable to monitor occupant location so that a caregiver or automated system can assess the need for a corrective or mitigating action.